Lesson 11, Part 4: Generating Parts of an SAS Statement Using a Macro

The macro below conditionally adds a variable (based on the parameter value to the macro call) in the PROC FREQ table statement.

• %sysfunc(ifc(condition, value_if_true, value_if_false)) is a way to do inline logic.
• %length(&row_var) checks if row_var is provided.
• If yes → row_var * smoking_status
• If no → just smoking_status

%let tbl = %sysfunc(ifc(%length(&row_var), &row_var * , ))smoking_status;
If row_var is empty → tbl = smoking_status
If row_var is specified → tbl = row_var * smoking_status

* Ex15_macro_part_of_SAS_statement.sas;
ods html close;  /* close default HTML to avoid clutter, optional */
options nocenter nodate nonumber symbolgen;
%macro run_freq(row_var);
   /* Build table expression dynamically */
   %let tbl = %sysfunc(ifc(%length(&row_var), &row_var * , ))smoking_status;

   
   /* Create a small dataset to display macro variable */
   data tbl_debug;
       length info $50;
       info = "&tbl";
   run;

   /* Print macro variable inline in Jupyter notebook */
    proc print data=tbl_debug noobs label;
       label info="DEBUG: TBL";
   run;


   /* Run PROC FREQ */
   proc freq data=sashelp.heart;
      tables &tbl;
   run;
%mend run_freq;

The SAS System

E3969440A681A2408885998500000051

%run_freq()
%run_freq(sex)
%run_freq(Weight_Status)

The SAS System

DEBUG: TBL
smoking_status

---

The SAS System

The FREQ Procedure

Smoking Status
Smoking_Status	Frequency	Percent	Cumulative Frequency	Cumulative Percent
Frequency Missing = 36
Heavy (16-25)	1046	20.22	1046	20.22
Light (1-5)	579	11.19	1625	31.41
Moderate (6-15)	576	11.13	2201	42.55
Non-smoker	2501	48.35	4702	90.90
Very Heavy (> 25)	471	9.10	5173	100.00

---

The SAS System

DEBUG: TBL
sex *smoking_status

---

The SAS System

The FREQ Procedure

Frequency Percent Row Pct Col Pct

Table of Sex by Smoking_Status Sex Smoking_Status(Smoking Status) Heavy (16-25) Light (1-5) Moderate (6-15) Non-smoker Very Heavy (> 25) Total Female 339 6.55 11.87 32.41 422 8.16 14.78 72.88 340 6.57 11.90 59.03 1682 32.51 58.89 67.25 73 1.41 2.56 15.50 2856 55.21     Male 707 13.67 30.51 67.59 157 3.03 6.78 27.12 236 4.56 10.19 40.97 819 15.83 35.35 32.75 398 7.69 17.18 84.50 2317 44.79     Total 1046 20.22 579 11.19 576 11.13 2501 48.35 471 9.10 5173 100.00 Frequency Missing = 36

---

The SAS System

DEBUG: TBL
Weight_Status *smoking_status

---

The SAS System

The FREQ Procedure

Frequency Percent Row Pct Col Pct

Table of Weight_Status by Smoking_Status Weight_Status(Weight Status) Smoking_Status(Smoking Status) Heavy (16-25) Light (1-5) Moderate (6-15) Non-smoker Very Heavy (> 25) Total Normal 381 7.37 26.06 36.42 171 3.31 11.70 29.58 234 4.53 16.01 40.70 543 10.51 37.14 21.73 133 2.57 9.10 28.36 1462 28.29     Overweight 618 11.96 17.52 59.08 375 7.26 10.63 64.88 306 5.92 8.68 53.22 1903 36.83 53.96 76.15 325 6.29 9.21 69.30 3527 68.26     Underweight 47 0.91 26.40 4.49 32 0.62 17.98 5.54 35 0.68 19.66 6.09 53 1.03 29.78 2.12 11 0.21 6.18 2.35 178 3.44     Total 1046 20.24 578 11.19 575 11.13 2499 48.36 469 9.08 5167 100.00 Frequency Missing = 42

%showLog